Study on the influence of frozen soil layer on seismic performance of railway gravity bridge piers with pile foundation
This paper aimed to investigate the seismic failure characteristics of the railway gravity piers with pile foundation under the influence of frozen soil layer and the influence of different influencing factors on the seismic performance of railway gravity piers with pile foundation in the seasonal frozen soil region.Firstly,the seismic damage characteristics of the railway gravity bridge pier with pile foundations in frozen soils were investigated by quasi-static model test.Secondly,a finite element model of bridge pier with pile foundation considering frozen soil effect was established.Then,the influence of the seasonal frozen soil layer thickness,shear-span ratio,axial compression ratio and bearing depth of pile cap on seismic performance of the railway gravity bridge pier with pile foundation was discussed by numerical simulation method.The results showed that the increase of seasonal frozen soil layer thickness in a certain range is beneficial to improve the seismic performance of the railway bridge pier with pile foundations,but if the frozen soil layer thickness increased beyond this range,its influence on the lateral bearing capacity of the bridge pier is weakened and the damage of pile-soil-pier system will be accelerated.Increasing the shear-span ratio and decreasing the embedded depth of the pile cap can significantly reduce the seismic performance of the bridge pier with pile foundations in frozen soils.Increasing the axial compression ratio can increase the lateral bearing capacity of the bridge pier with pile foundations,but it will accelerate the appearance of peak load of the bridge pier with pile foundations and accelerate the damage of the pile-soil-pier system.
seasonal frozen soilpile foundationrailway gravity pierseismic performancehysteretic energy dissipation characteristics